The daughter of two Wellington lawyers has pleaded guilty to drink-driving but a charge of injuring a man she hit with her car has been withdrawn by police.

Sophia Cara Ord Nisbet, 18, who was in her final year of high school, had been driving along Marine Parade at 12.15am on October 28. She had been at the Worser Bay Lifesaving club at a private party and had been drinking.

St Patrick's College pupil James Dumelow, 18, had been at the same party and then walked along the shoreline parallel to Marine Parade. He walked up from the beach and into the road.

The police summary of facts said Nisbet had no time to react and hit Dumelow who sustained multiple fractures to his skull, a broken shin and cuts.

Nisbet was breath-tested and found to have a reading of 641 micrograms per litre of breath. The legal limit for someone under 20 is zero.

She admitted she should not have been drinking.

Police withdrew the previous charge of careless driving causing injury, accepting that she could not have altered what happened.

Wellington District Court judge John Walker fined her $400 and disqualified her from driving for six months.